High-temperature low-dielectric-loss high-electrical-property medium-voltage ethylene-propylene insulating rubber cable material and preparation method thereof

Abstract

The invention provides a medium-voltage ethylene-propylene insulating rubber cable material with high temperature, low dielectric loss and high electrical property, and belongs to the field of materials. The ethylene-propylene insulating rubber cable material comprises the following components in parts by weight: 70-100 parts of ethylene propylene diene monomer, 0-30 parts of low-density polyethylene, 2-5 parts of a vulcanizing agent, 0-2 parts of a co-vulcanizing agent, 5-10 parts of a vulcanization accelerator, 30-60 parts of filler, 1-3 parts of an antioxidant, 10-20 parts of a softening agent, 5-10 parts of a stabilizer and 0-0.5 part of a scorch retarder, the ethylene propylene diene monomer is produced by a vanadium catalyst, and the filler is calcined mica powder. The calcined mica powder has excellent electrical insulating property, and the electrical property of ethylene-propylene rubber produced by the vanadium catalyst is better; cleanness control in the production process has great influence on the electrical property of the material.

Description

Technical Field

[0001] The present invention belongs to the field of materials, and relates to a medium-voltage ethylene-propylene insulating rubber cable material with high temperature, low dielectric loss and high electrical performance, and a preparation method thereof. Technical Background

[0002] In modern life, electricity is widely used. Whether it is industrial construction, agricultural production, scientific research, or daily life, electricity is indispensable. Therefore, as a carrier for transmitting and distributing electric energy, wire and cable play an important role in modern society. In order to increase the capacity and distance of transmitting electric energy, people have continuously improved the cable insulation. At present, the highest voltage level of AC cables is 1000 kV, and the highest voltage level of DC cables is ±800 k. In addition to these extra-high voltage transmission cables, medium- and high-voltage cables with a voltage level of 35 kV and below are more widely used in public utilities. Due to its excellent electrical insulation, good ozone resistance, moisture resistance, cold resistance, aging resistance and other properties, as well as the development of technologies in rubber production, processing, mixing and vulcanization processes, ethylene-propylene rubber is widely used in medium- and high-voltage and even extra-high voltage cables.

[0003] The dielectric loss of a material refers to the loss caused by the movement of charged particles (weakly bound electrons and weakly associated ions, including holes and vacancies) during the conduction and polarization processes caused by the conductance and relaxation polarization of the medium. Since the rotation orientation of the dipole lags behind the change of the AC electric field, the dipole is forced to vibrate, and a part of the electric energy is absorbed and converted into heat energy during each alternating process. Dielectric loss is one of the important quality indicators of dielectrics. Dielectric loss not only consumes electric energy, but also causes the cable to heat up and the temperature to rise. The generated heat will seriously limit the transmission capacity and service life of the cable. The dielectric loss factor reflects the loss characteristics of the insulating material. The smaller the dielectric loss factor, the better, which can reduce the power consumption and delay the aging caused by insulation heating.

[0004] Although ethylene-propylene rubber has excellent electrical insulation, its processing performance is poor and the cost is high. It cannot be used directly like polyethylene and polypropylene. Fillers need to be added to the system to increase the volume, reduce the cost, and improve the processing performance, such as reducing the shrinkage rate of semi-finished products, improving the surface flatness of semi-finished products, increasing the hardness and modulus at a specified elongation of vulcanized rubber, etc. Fillers have a great influence on the processing performance of unvulcanized rubber, the physical and mechanical properties, dynamic mechanical properties and electrical properties of vulcanized rubber. At the same time, the addition of fillers is equivalent to impurities, which will cause an increase in the dielectric loss of the material; under the action of a certain electric field, as the temperature rises, the dielectric properties of ethylene-propylene rubber change, especially its dielectric loss increases significantly, which is prone to thermal breakdown. Summary of the Invention

[0005] In view of the problems existing in the prior art, the present invention provides a medium-voltage ethylene-propylene insulating rubber cable material with high temperature, low dielectric loss and high electrical performance.

[0006] It is composed of ethylene-propylene insulating rubber cable compound, by weight parts as follows:

[0007] 70 - 100 parts of ethylene-propylene-diene monomer rubber,

[0008] 0 - 30 parts of low-density polyethylene,

[0009] 2 - 5 parts of vulcanizing agent,

[0010] 0 - 2 parts of co-vulcanizing agent,

[0011] 5 - 10 parts of vulcanization accelerator,

[0012] 30 - 60 parts of filler,

[0013] 1 - 3 parts of antioxidant,

[0014] 10 - 20 parts of softening agent;

[0015] 5 - 10 parts of stabilizer;

[0016] 0 - 0.5 part of scorch retarder.

[0017] The ethylene-propylene-diene monomer rubber is produced by a vanadium-based catalyst, the filler is calcined mica powder, the vulcanizing agent is dicumyl peroxide, the co-vulcanizing agent is triallyl isocyanurate; the vulcanization accelerator is nano-zinc oxide, the antioxidant is 2,2,4-trimethyl-1,2-dihydroquinoline polymer; the softening agent is a mixture of rubber protection wax, oxidized polyethylene wax, methyl silicone oil and paraffin oil in a mass ratio of 5:5:1:(0 - 5); the stabilizer is lead oxide or lead oxide masterbatch.

[0018] The scorch retarder is a multi-functional nitroxide free radical mixture. The scorch retarder first captures free radicals during the production process, reacts with free radicals, delays the start of the crosslinking reaction, and prevents early vulcanization of the rubber during processing.

[0019] In one embodiment, the composition is specifically:

[0020] 70 parts of ethylene-propylene-diene monomer rubber,

[0021] 30 parts of low-density polyethylene

[0022] 3.5 parts of dicumyl peroxide,

[0023] 5 parts of zinc oxide,

[0024] 50 parts of calcined mica powder,

[0025] 1 part of 2,2,4-trimethyl-1,2-dihydroquinoline polymer,

[0026] 5 parts of rubber protection wax,

[0027] 5 parts of oxidized polyethylene wax

[0028] 1 part of dimethyl silicone oil,

[0029] 5 parts of red lead masterbatch,

[0030] 0.3 part of scorch retarder.

[0031] The second object of the present invention is to provide a method for preparing the above-mentioned medium-voltage ethylene-propylene insulating rubber cable material with high temperature, low dielectric loss and high electrical performance,

[0032] Step 1, mixing: Add ethylene-propylene-diene monomer rubber and low-density polyethylene into an internal mixer for mixing; after the materials are sufficiently mixed, add fillers, vulcanizing agents, antioxidants, vulcanization accelerators, softeners, stabilizers and scorch retarders into the internal mixer at one time for mixing; mix the materials until they are uniform, reduce the rotation speed, add the vulcanizing agent, mix evenly, remove the mixed materials from the internal mixer, place them on a two-roll open mill for mixing, add the mixed rubber materials into a rubber filter for filtering, and obtain the mixed materials by passing the filtered rubber materials through a three-roll calender for sheet making;

[0033] Step 2, pelletizing: Pelletize the materials after mixing and calendering by using a gear pump rubber extruder, and obtain semi-finished particles through a cooling system and a collection system;

[0034] Step 3, extrusion molding: Let the semi-finished particles stand, and use a rubber screw extruder to extrude the particles to obtain the insulating material.

[0035] In one embodiment, the specific content of Step 1 is: Add ethylene-propylene-diene monomer rubber and low-density polyethylene into an internal mixer for mixing for 3-5 minutes; after the materials are sufficiently mixed, add zinc oxide, 2,2,4-trimethyl-1,2-dihydroquinoline polymer, rubber protective wax, oxidized polyethylene wax, dimethyl silicone oil, calcined mica powder, red lead masterbatch and scorch retarder into the internal mixer at one time, gradually increase the rotation speed to 40 rpm, mix for 8 minutes until the materials are uniform, and the temperature during the whole mixing process must be controlled within 125°C; reduce the rotation speed to 20 rpm, add dicumyl peroxide, mix for about 1 minute, and the temperature must be controlled within 125°C. Finally, remove the mixed materials from the internal mixer, place them on a two-roll open mill for mixing, add the mixed rubber materials into a UTH gear pump rubber filter for filtering, control the temperature of the rubber filter within 100°C, and then obtain the mixed materials by passing the filtered rubber materials through a three-roll calender for sheet making.

[0036] Beneficial effects:

[0037] 1. Calcined mica powder has excellent electrical insulation, and its cleanliness has a great influence on the dielectric loss;

[0038] The ethylene-propylene rubber produced by the vanadium-based catalyst has better electrical properties (the cleaner the catalyst post-treatment, the smaller the dielectric loss);

[0039] The cleanliness control during the production process has a great influence on the electrical properties of the material.

[0040] 2. Since the core insulation cortex produced is relatively thick, in order to achieve sufficient vulcanization, the production speed is slow. The addition of the scorch retarder first captures free radicals during the production process. Reacting with free radicals delays the start of the crosslinking reaction and prevents early vulcanization of the rubber during processing. Specific implementation mode

[0041] It should be noted that the raw materials used in the present invention are all ordinary commercially available products, and no specific limitation is imposed on their sources.

[0042] Example 1:

[0043] 70 parts of ethylene-propylene-diene monomer rubber (2470E, Arlanxeo, vanadium-based catalyst system),

[0044] 30 parts of low-density polyethylene

[0045] 3.5 parts of dicumyl peroxide,

[0046] 5 parts of nano-zinc oxide,

[0047] 50 parts of calcined mica powder (LingShou Huixin),

[0048] 1 part of 2,2,4-trimethyl-1,2-dihydroquinoline polymer,

[0049] 5 parts of rubber protection wax (Lanxess Antilux654),

[0050] 5 parts of oxidized polyethylene wax (805, Qingdao Sino),

[0051] 1 part of dimethyl silicone oil (201 silicone oil, Hangzhou Yongming Organosilicon Co., Ltd.),

[0052] 5 parts of lead oxide masterbatch (P-80, Shanghai Weijie),

[0053] 0.3 part of scorch retarder (ZX-3001, Shanghai Paiyuan).

[0054] The high electrical performance medium voltage ethylene-propylene insulation rubber cable material is prepared according to the following method:

[0055] 1) Weighing materials: Accurately weigh various materials according to the formula for standby;

[0056] 2) Kneading: First, add ethylene propylene diene monomer (EPDM) and low-density polyethylene (LDPE) into an internal mixer and knead for 5 min. After the materials are sufficiently kneaded, add vulcanization accelerators, fillers, antioxidants, stabilizers, softeners, scorch inhibitors, etc. into the internal mixer at one time. Gradually increase the rotation speed to 40 rpm and knead for 8 min until the materials are uniform. The temperature during the whole kneading process must be controlled within 125 °C. Reduce the rotation speed to 20 rpm, add dicumyl peroxide, and knead for 1 min. The temperature must be controlled within 125 °C. Finally, remove the kneaded materials from the internal mixer and knead them on a two-roll mill. Add the kneaded rubber material into a UTH gear pump rubber filter to filter the rubber. The temperature of the rubber filter is controlled within 100 °C. Obtain the kneaded materials by passing the rubber material after filtering through a three-roll calender and slicing;

[0057] 3) Pelletizing: The materials after kneading and calendering are pelletized by a gear pump rubber extruder, and semi-finished pellets are obtained through a cooling system and a collection system to obtain the insulating material.

[0058] Comparative Example 1:

[0059] 70 parts of ethylene propylene diene monomer (2470C, Arlanxeo, controlled long-chain branching technology),

[0060] 30 parts of low-density polyethylene

[0061] 3.5 parts of dicumyl peroxide, 5 parts of zinc oxide,

[0062] 50 parts of calcined mica powder (LingShou Huixin),

[0063] 1 part of 2,2,4-trimethyl-1,2-dihydroquinoline polymer,

[0064] 5 parts of rubber protective wax (Rhein Chemie Antilux654),

[0065] 5 parts of oxidized polyethylene wax (805, Qingdao Sainuo)

[0066] 1 part of dimethyl silicone oil (201 silicone oil, Hangzhou Yongming Organosilicon Co., Ltd.), 5 parts of lead dioxide masterbatch (P-80, Shanghai Weijie),

[0067] 0.3 part of scorch inhibitor (ZX-3001, Shanghai Paiyuan).

[0068] The preparation method is the same as that of Example 1.

[0069] Comparative Example 2:

[0070] 70 parts of ethylene propylene diene monomer (2032PM, Sinopec Mitsui, metallocene catalyst system), 30 parts of low-density polyethylene

[0071] 3.5 parts of dicumyl peroxide, 5 parts of zinc oxide,

[0072] 50 parts of calcined mica powder (Lingshou Huixin),

[0073] 1 part of 2,2,4-trimethyl-1,2-dihydroquinoline polymer,

[0074] 5 parts of rubber protective wax (Lanxess Antilux 654),

[0075] 5 parts of oxidized polyethylene wax (805, Qingdao Sainuo)

[0076] 1 part of dimethyl silicone oil (201 silicone oil, Hangzhou Yongming Organosilicon Co., Ltd.), 5 parts of lead dioxide masterbatch (P-80, Shanghai Weijie),

[0077] 0.3 part of scorch retarder (ZX-3001, Shanghai Paiyuan).

[0078] The preparation method is the same as that of Example 1.

[0079] Comparative Example 3:

[0080] 70 parts of ethylene propylene diene monomer rubber (KEP-020P, Kumho Korea),

[0081] 30 parts of low density polyethylene

[0082] 3.5 parts of dicumyl peroxide,

[0083] 5 parts of zinc oxide,

[0084] 50 parts of calcined mica powder (Lingshou Huixin),

[0085] 1 part of 2,2,4-trimethyl-1,2-dihydroquinoline polymer,

[0086] 5 parts of rubber protective wax (Lanxess Antilux 654),

[0087] 5 parts of oxidized polyethylene wax (805, Qingdao Sainuo) 1 part of dimethyl silicone oil (201 silicone oil, Hangzhou Yongming Organosilicon Co., Ltd.), 5 parts of lead dioxide masterbatch (P-80, Shanghai Weijie),

[0088] 0.3 part of scorch retarder (ZX-3001, Shanghai Paiyuan).

[0089] The preparation method is the same as that of Example 1.

[0090] Comparative Example 4:

[0091] 70 parts of ethylene propylene diene monomer rubber (2470E, Arlanxeo, vanadium catalyst system), 30 parts of low density polyethylene

[0092] 3.5 parts of dicumyl peroxide,

[0093] 5 parts of zinc oxide,

[0094] 50 parts of calcined kaolin (JD-80A, Jin Yu, Shanxi), 1 part of 2,2,4-trimethyl-1,2-dihydroquinoline polymer,

[0095] 5 parts of rubber protective wax (Rhein Chemie Antilux 654),

[0096] 5 parts of oxidized polyethylene wax (805, Qingdao Sino), 1 part of dimethyl silicone oil (201 silicone oil, Hangzhou Yongming Organosilicon Co., Ltd.), 5 parts of lead dioxide masterbatch (P-80, Shanghai Weijie),

[0097] 0.3 part of scorch retarder (ZX-3001, Shanghai Paiyuan).

[0098] The preparation method is the same as that of Example 1.

[0099] Comparative Example 5:

[0100] 70 parts of ethylene propylene diene monomer rubber (2470E, Arlanxeo, vanadium-based catalyst system), 30 parts of low-density polyethylene

[0101] 3.5 parts of dicumyl peroxide,

[0102] 5 parts of zinc oxide,

[0103] 60 parts of calcined mica powder (Lingshou Huixin),

[0104] 1 part of 2,2,4-trimethyl-1,2-dihydroquinoline polymer,

[0105] 5 parts of rubber protective wax (Rhein Chemie Antilux 654),

[0106] 5 parts of oxidized polyethylene wax (805, Qingdao Sino), 1 part of dimethyl silicone oil (201 silicone oil, Hangzhou Yongming Organosilicon Co., Ltd.), 5 parts of lead dioxide masterbatch (P-80, Shanghai Weijie),

[0107] 0.3 part of scorch retarder (ZX-3001, Shanghai Paiyuan).

[0108] The preparation method is the same as that of Example 1.

[0109]

[0110]

[0111] Comparing the data of Comparative Example 1 and Comparative Examples 1-5, it can be clearly seen that the performance of ethylene-propylene rubber 2470E produced by traditional vanadium-based catalysts is superior to that of ethylene-propylene rubber 2032PM produced by metallocene catalyst systems and ethylene-propylene rubber 2470C with controlled long-chain branching technology. The performance of calcined mica powder is superior to that of calcined kaolin JD-80A, and the more the filler dosage, the worse the electrical properties, especially the dielectric loss tanσ at 95°C.

[0112] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the purpose and scope of the technical solutions of the present invention, and they should all be covered by the scope of the claims of the present invention.

Claims

1. A medium-voltage ethylene-propylene insulated rubber cable compound with high temperature resistance, low dielectric loss and high electrical performance, characterized in that, The composition of ethylene-propylene insulating rubber cable material is as follows by weight parts: 70 - 100 parts of ethylene-propylene-diene monomer rubber, 0 - 30 parts of low-density polyethylene, 2 - 5 parts of vulcanizing agent, 0 - 2 parts of co-vulcanizing agent, 5 - 10 parts of vulcanization accelerator, 30 - 60 parts of filler, 1 - 3 parts of antioxidant, 10 - 20 parts of softening agent; 5 - 10 parts of stabilizer; 0 - 0.5 parts of scorch retarder. The ethylene-propylene-diene monomer rubber is produced by a vanadium-based catalyst, the filler is calcined mica powder, the vulcanizing agent is dicumyl peroxide, the co-vulcanizing agent is triallyl isocyanurate; the vulcanization accelerator is nano-zinc oxide, the antioxidant is 2,2,4-trimethyl-1,2-dihydroquinoline polymer; the softening agent is a mixture of rubber protective wax, oxidized polyethylene wax, dimethyl silicone oil and paraffin oil in a mass ratio of 5:5:1:(0 - 5); the stabilizer is lead oxide red or lead oxide red masterbatch.

2. The medium voltage ethylene-propylene insulated rubber cable compound with high temperature, low dielectric loss and high electrical performance according to claim 1, characterized in that, The specific composition is as follows: 70 parts of ethylene-propylene-diene monomer rubber, 30 parts of low-density polyethylene 3.5 parts of dicumyl peroxide, 5 parts of nano-zinc oxide, 50 parts of calcined mica powder, 1 part of 2,2,4-trimethyl-1,2-dihydroquinoline polymer, 5 parts of rubber protective wax, 5 parts of oxidized polyethylene wax 1 part of dimethyl silicone oil, 5 parts of lead oxide red masterbatch, 0.3 parts of scorch retarder.

3. The preparation method of the high-temperature, low dielectric loss and high electrical performance medium-voltage ethylene-propylene insulating rubber cable material according to claim 1 or 2, characterized in that, Step 1, mixing: Add ethylene-propylene-diene monomer rubber and low-density polyethylene into an internal mixer for internal mixing; after the materials are sufficiently internally mixed, add the filler, vulcanizing agent, antioxidant, co-vulcanizing agent, vulcanization accelerator, softening agent, stabilizer and scorch retarder into the internal mixer at one time for mixing; mix the materials until uniform, reduce the rotation speed, add the vulcanizing agent, mix evenly, remove the mixed materials from the internal mixer, place them on a two-roll mill for mixing, add the mixed rubber materials into a rubber filter for filtering, and obtain the mixed materials by passing the filtered rubber materials through a three-roll calender for sheet making; Step 2, granulating: The materials after mixing and calendering are granulated by a gear pump rubber extruder, and semi-finished particles are obtained through a cooling system and a collection system; Step 3, extrusion molding: The semi-finished particles are parked, and the particles are extruded by a rubber screw extruder to obtain the insulating material.

4. The preparation method of the medium-voltage ethylene-propylene insulating rubber cable material with high temperature, low dielectric loss and high electrical properties according to claim 3, characterized in that, The specific steps of Step 1 are as follows: Add ethylene propylene diene monomer rubber and low-density polyethylene into an internal mixer and knead for 3 - 5 minutes; after the materials are kneaded sufficiently, add nano-zinc oxide, 2,2,4-trimethyl-1,2-dihydroquinoline polymer, rubber protective wax, oxidized polyethylene wax, dimethyl silicone oil, calcined mica powder, triallyl isocyanurate, paraffin oil, lead dioxide masterbatch, and anti-scorching agent into the internal mixer at one time, gradually increase the rotational speed to 40 rpm, and knead for 8 minutes until the materials are uniform. The temperature during the entire kneading process must be controlled within 125°C; reduce the rotational speed to 20 rpm, add dicumyl peroxide, and knead for about 1 minute. The temperature must be controlled within 125°C. Finally, remove the kneaded materials from the internal mixer and knead them on a two-roll mill. Add the kneaded rubber materials into a UTH gear pump rubber filter to filter the rubber. The temperature of the rubber filter is controlled within 100°C. After that, pass the rubber materials after filtering through a three-roll calender to obtain the kneaded materials.

Images